滨海软土冻结温度场发展规律

Development characteristics of freezing temperature field of coastal soft soil strata

为研究滨海软土地层中联络通道冻结温度场的发展规律,以上海轨道交通15号线罗秀路站至百色路站区间联络通道为工程背景,对冻结帷幕厚度、平均温度及冻结过程进行分析,通过建立联络通道三维数值模型预测冻结温度场发展规律,并与实测温度数据进行分析验证。结果表明:地层中存在固有压力导致泄压孔含有初始压力值,埋设冻结管时注入大量水泥浆将抑制地层中水分迁移,减小冻结过程冻胀影响;冻结过程地层温度下降规律可分为温度快速下降、降温速度减小后增大、降温速度缓慢减小、温度稳定4个阶段;冻结帷幕内外侧发展速度比例为1.42︰1,灰色粉土比粉质黏土夹粉土冻结效果好,粉质黏土夹粉土发展速度为20.02mm/d,灰色粉土发展速度为29.75 mm/d。

In order to research the temperature fields and development law of freezing in the construction of connected aisle in coastal soft soil stratum,based on connected aisle between Luoxiu road station and Baise road station of Shanghai subway Line 15,the thickness and average temperature of frozen curtain,and the freezing process were analyzed.The temperature fields and development law of freezing were predicted by the three-dimensional numerical model of the connected aisle and the temperature data which were analyzed.The results show that the inherent pressure in soft soil causes initial pressure in the pressure relief hole.A lot of cement paste was injected during the burial of the freezing tubes,which will inhibit water migration and reduce the effect of frost heaving during the freezing process.The process of freezing can be divided into four stages by temperature:rapid drop of temperature,drop of temperature decreases first and then increases,slow drop of temperature,temperature stability.The rate of development speed of frozen inside and outside curtain is 1.42︰1.The grey silt freezes faster than silty clay with silt.The development freezing speed of silty clay with silt and grey silt are 20.02 mm/d and 29.75 mm/d.